Mac Mail "cannot send message" in reply to an account (of 3 I use) because it was rejected by the server

Hi Loisbikelane,

Thanks for contacting Apple Support Communities!

We understand that you're unable to send mail from one account on your Mac.

If you're unsure of the email settings you should be using, you can either contact your email provider or you can enter your email address here to locate your mail settings: Mail - Official Apple Support

This is also a handy resource to help you to troubleshoot Mail on your Mac: If you can’t send or receive email on your Mac - Apple Support

"Test using webmail

Many email providers offer webmail, which is a way to use email with a web browser such as Safari, instead of with an email app such as Mail. For example, if you're using an iCloud Mail account, you can use iCloud.com to send and receive email.

Webmail is a good way to verify that your account is valid, but it doesn't mean that your account is set up correctly in Mail. Your email provider can help you verify your email settings and check for other issues that affect sending or receiving email.

Remove your email account, then add it back

If no other solutions work, follow these steps:

1. Remove your email account in Mail.
2. Add your email account in Mail again.
3. Try to send and receive email."

We hope this helps you.

Cheers!

Hey Loisbikelane,

The Mail app allows you to have multiple e-mail accounts in one place. The Mail app isn't associated with any email service provider. You will need to add your existing email accounts, including iCloud mail if you use it.

* The first time you open Mail, you may be asked to add an account. Select an account type or Other Mail Account, then enter your account information.

* If you already added an email account, you can still add more. In Mail, choose Mail > Add Account, select an account type, then enter your account information. Make sure the Mail checkbox is selected for the account.

* If you’re using an account on your Mac with other apps, such as Contacts or Messages, you can also use that account with Mail. In Mail, choose Mail > Accounts to open Internet Accounts settings, then click Add Account on the right.

* You can set options for your email accounts in Mail settings.

The information above and other information that may interest you are included in this Mail app User Guide. What’s new in Mail on Mac? To ensure you're getting the correct information for your macOS, make sure the correct version is selected.

Some email accounts will automatically enter the server settings, however some may need the information entered manually. This information is provided by the Email Service Provider. If you do not have that information and unable to find it, contact the Email Service Provider to get the information.

Hope this helps. Take care.

Loisbikelane wrote:

Thanks!

So if it's the built-in Mac Mail that comes with this Macbook Pro, who would be the email provider? I had assumed it was Apple.

I followed the online instructions for setting up the account (using OS 12.6.3), but none of the servers or other details were present in the dialog box for me to choose from.

I've also used the browser version for my email account(s) when Mac Mail is acting up, but I dislike being distracted by the ads in the sidebar.

Q - " So if it's the built-in Mac Mail that comes with this Macbook Pro, who would be the email provider? I had assumed it was Apple. "

Q - " in reply to an account (of 3 I use) "

A - What is appearing in System Preferences >> Internet Accounts ?

Image below

Which Account is set as the Default Account in Apple Mail

In image below, as I only use one e-mail account the information may not be specific to your setup

Incase wondering - Yes have there domains all Associated to Apple iCloud

One from decades ago with the xx@mac.com and one xx@me.com and one from xx@icloud

As long as the Screen Shot does not contain Personal Information that could clearly Identify You - it should be permissible

Sorry but with out knowing who the 3 e-mail accounts are associated with it is a shot in the dark